The moisture content of cotton fibers as they are processed through either a cotton gin or a cotton mill is preferably monitored and controlled. The amount of moisture within the cotton tends to have a great influence on various qualities of the cotton as it is processed. For example, the cotton fibers tend to break more readily if the moisture content drops too far during processing. As the cotton fibers during such processing are often carried along in air streams and subjected to heat, the moisture content can easily drop and the quality of the cotton fibers can easily be degraded if sufficient care is not taken to avoid such occurrences.
There are many places during such processing where it is desirable to take moisture readings on the cotton fibers. For example, moisture sensors have been developed to capture and sense the moisture in airborne fibers as they flow through the cotton gin. Another place where moisture readings are often taken is near the end of the ginning process, in order to determine the final moisture content of the bale. One place for measuring the cotton moisture content for the bale is where the cotton fibers are formed into bales in a tramper, prior to being strapped in a bale press and optionally wrapped. Moisture sensors have been developed to measure moisture by pressing into the cotton fibers while the cotton is being tramped to prepare it for being pressed into a bale.
The moisture sensors as described above are generally devices that function by measuring the electrical resistance between two or more electrodes. For the tramper moisture sensor, the electrodes are typically driven into a mass of the cotton fibers, and a current is run between the electrodes through the cotton mass. The moisture content of the fiber mass is determined by a correlation with one or more properties of the electrical resistance that is measured between the electrodes that penetrate the fiber mass.
However, there tend to be problems associated with such tramper moisture sensors for determining final bale moisture. One problem, for example, is that if the cotton fibers are sprayed with water for moisture restoration prior to exiting the tramper, the cotton fibers tend to become entangled and retained to some degree in the electrodes. Thus, the moisture readings are influenced, at least in part, by the same mass of fibers from reading to reading, until the retained fiber mass is removed from the electrodes.
What is needed, therefore, is a system by which moisture content readings can be taken on a large volume, such as a cotton bale, where the moisture sensor is not clogged by material from the volume, and where the readings tend to be more representative of the overall moisture content of the volume.